Native or Invader? Know the Enemy
Hint: Invasive fire ants produce mounds of trouble

IMAGE: 2010 © Imagemania |

Native fire ants actually help impede the spread of invasive species, so before attacking that mound, make sure it contains the real enemy. (Remember that native species never reached pest status thanks to control by their natural enemies.)

Fire ants’ signature behavior is attacking en masse when the mound is disturbed. Fire ants live and do most of their foraging underground, and nests form a network of tunnels up to 18 inches in diameter and 36 inches deep. The mound above ground is soil from the clearing of tunnels and chambers underground. The ants live in this above-ground mound certain times of the year.

Invasive ants also are known for their numerous, conspicuous mounds of loose soil above ground, and their workers sting aggressively and repeatedly. Find information about other native species of ants in Texas at

To learn more about the presence of phorid flies in a particular area and details on the release program, go to

Sizing Up Fire Ants

Both species range in size from approximately 1/8 to 3/8 of an inch.

Native fire ants
(Solenopsis geminata)

This species is typified by two size classes: small workers and large majors. Often these ants are uniformly reddish-brown. The head width of the majors is much wider than their abdomens.

Non-native fire ants (Solenopsis invicta)

Red imported fire ant worker sizes range from small to large. The workers are usually dark brown with brown-black abdomens. The head widths of all workers are about the same as their abdomens.

TAGS: Nature, Outdoors

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